Insulating Ductwork In Attic Venting

The 1 800 square foot brick ranch in climate zone 4 dates from the 1960s but the previous owner installed both a furnace and ductwork in the attic just four years ago.

Insulating ductwork in attic venting.

Ted also has inherited a powered attic ventilator. Use the type of metallic foil duct tape recommended by the insulation manufacturer to seal and hold the insulation in place. Because the moving air is in the ductwork for only a short period of time it does not need the insulation r value the attic floor requires. Other times insulation may be on the outside.

The greater the temperature extreme between the air inside the duct and the air surrounding the ductwork the greater your need for duct insulation. Unfortunately so many houses especially newer homes end up with ductwork running through the attic. Although both the attic floor and the ductwork are insulated ted recognizes the situation isn t ideal. Purchase duct wrap insulation that complies with the 2009 international energy conservation code iecc standards that specify an r value of 8 for attic ducts and 6 for ducts located anywhere else.

Make sure the foil surface of the insulation is free of dust before applying the tape. Install ductwork so that it is in direct contact with i e laying on the ceiling and or truss lower cords. Sometimes the insulation is inside the ductwork.